Cellphone Notification Trolling

If you want to really mindfuck someone, learn to imitate their cellphone's notification noises. It's the kind of prank that has the power to send any potential victim into a Pavlov fit of insanity, or at the very least piss them off until they catch on. That's exactly what Manfred Hanberg did to his friend who has no idea he's been trolled until after checking his phone several times.